/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package pl.otros.logview.accept.query.org.apache.log4j.rule;

import pl.otros.logview.LogData;

import java.util.*;

/**
 * A Rule class implementing a logical 'and'.
 * 
 * @author Scott Deboy (sdeboy@apache.org)
 * @author Krzysztof Otrebski
 */
public class AndRule extends AbstractRule {

  /**
   * First rule.
   */
  private final Rule firstRule;
  /**
   * Second rule.
   */
  private final Rule secondRule;
  /**
   * Serialization id.
   */
  static final long serialVersionUID = -8233444426923854651L;

  /**
   * Create new instance.
   * 
   * @param first
   *          first rule.
   * @param second
   *          second rule.
   */
  private AndRule(final Rule first, final Rule second) {
    super();
    this.firstRule = first;
    this.secondRule = second;
  }

  /**
   * Create rule from top two elements of stack.
   * 
   * @param stack
   *          stack of rules.
   * @return Rule that evaluates true only if both rules are true.
   */
  public static Rule getRule(final Stack<Object> stack) {
    if (stack.size() < 2) {
      throw new IllegalArgumentException("Invalid AND rule - expected two rules but received " + stack.size());
    }
    Object o2 = stack.pop();
    Object o1 = stack.pop();
    if ((o2 instanceof Rule) && (o1 instanceof Rule)) {
      Rule p2 = (Rule) o2;
      Rule p1 = (Rule) o1;
      return new AndRule(p1, p2);
    }
    throw new IllegalArgumentException("Invalid AND rule: " + o2 + "..." + o1);
  }

  /**
   * Get rule.
   * 
   * @param firstParam
   *          first rule.
   * @param secondParam
   *          second rule.
   * @return Rule that evaluates true only if both rules are true.
   */
  public static Rule getRule(final Rule firstParam, final Rule secondParam) {
    return new AndRule(firstParam, secondParam);
  }

  /**
   * {@inheritDoc}
   */
  @SuppressWarnings({ "rawtypes", "unchecked" })
  public boolean evaluate(final LogData event, Map matches) {
    if (matches == null) {
      return firstRule.evaluate(event, null) && secondRule.evaluate(event, null);
    }
    Map tempMatches1 = new HashMap();
    Map tempMatches2 = new HashMap();
    boolean result = firstRule.evaluate(event, tempMatches1) && secondRule.evaluate(event, tempMatches2);
    if (result) {
      for (Iterator iter = tempMatches1.entrySet().iterator(); iter.hasNext();) {
        Map.Entry entry = (Map.Entry) iter.next();
        Object key = entry.getKey();
        Set value = (Set) entry.getValue();
        Set mainSet = (Set) matches.get(key);
        if (mainSet == null) {
          mainSet = new HashSet();
          matches.put(key, mainSet);
        }
        mainSet.addAll(value);
      }
      for (Iterator iter = tempMatches2.entrySet().iterator(); iter.hasNext();) {
        Map.Entry entry = (Map.Entry) iter.next();
        Object key = entry.getKey();
        Set value = (Set) entry.getValue();
        Set mainSet = (Set) matches.get(key);
        if (mainSet == null) {
          mainSet = new HashSet();
          matches.put(key, mainSet);
        }
        mainSet.addAll(value);
      }
    }
    return result;
  }
}
